Conventional wisdom says that if you want to be richer, a useful thing
to do is get married. Life is cheaper when there's only one mortgage to pay
and someone else can do certain tasks  cooking, say, or car repair  more
efficiently than you. Research by Ohio State University's Jay Zagorsky shows
that married baby boomers increase their wealth an average 16% a year, while those
who are single increase their net worth at half that rate. (Read "Is There Hope for the American Marriage?")

Yet the economic benefit of marriage isn't what it used to be. In a
chapter of a book newly out from the Russell Sage Foundation, Changing
Poverty, Changing Policies, two social scientists show that the
marriage premium has subsided since 1969. Maria Cancian, a professor of public affairs
and social work at the University of WisconsinMadison, and Deborah Reed,
director of research at Mathematica Policy Research, set out to study how
the changing makeup of American families has affected the number of people
below the poverty line. Considering how the rate of marriage has fallen and
the rate of divorce has risen, the researchers expected the number of people
living below the poverty line to grow 2.6%. But when they looked at the
data, poverty had increased by less than half that amount. (See photos of Carley Roney and David Liu, co-founders of the Knot.)

Why? In a nutshell, because single women, even those with kids,
have an easier time supporting themselves outside marriage than they used
to. More women are working, increasingly for wages that are
competitive with those of men. Women are having children later in life, and
fewer of them. On top of that, a growing percentage of women who have
children but aren't married don't live on their own. In 1970, 62% of single
mothers were the only adult in their household, but by 2006, just 55% were
living without another means of support  thanks to more women cohabitating
with a male partner or grandparent. (See photos of the busiest wedding day in history: 7/7/07.)

Now, that's not to say marriage doesn't coincide with significant economic
benefits. As research by Zagorsky and others illustrates, it does. A child
in a single-parent family, for instance, is five times as likely to live
below the poverty line. What Cancian and Reed try to illustrate, though, is
that replicating marriage wouldn't necessarily generate more per-person
wealth. "There are reasons some people don't get married  they don't have the
same options," says Cancian. Marrying someone who is chronically unemployed or incarcerated  might very well not be an economic step up. (See a gay-wedding video.)

A better policy response, the researchers hold, is to address the variable
that has partly been holding poverty at bay the past few decades: women in
the workforce. Policies designed to make it easier for a person to have a
job while rearing a child  flexible work schedules, on-site day care  could be
a way to let unmarried individuals recapture some of the advantage of
marriage. The issue is hardly fringe: last year, some 40% of children were
born outside of marriage. "We have to build a system where people can be
both good workers and good parents," says Cancian.